Ensure all Location subclasses implement hashCode() and equals()

* And simplify toString().
* Add hashCode() for Location subclasses defining equals().

Author: eregon

truffle/src/com.oracle.truffle.api.object/src/com/oracle/truffle/api/object/ExtLocations.java

@@ -199,7 +199,7 @@ public final void set(DynamicObject store, Object value, boolean guard, boolean
 
         @Override
         public String toString() {
-            return "=" + String.valueOf(value);
+            return "=" + value;
         }
 
         @Override
@@ -369,12 +369,7 @@ public boolean equals(Object obj) {
 
         @Override
         public String toString() {
-            return super.toString() + ("[final=" + isAssumedFinal() + "]");
-        }
-
-        @Override
-        public String getWhereString() {
-            return this instanceof ArrayLocation ? ("[" + index + "]") : ("@" + index);
+            return super.toString() + (this instanceof ArrayLocation ? ("[" + index + "]") : ("@" + index)) + ("[final=" + isAssumedFinal() + "]");
         }
 
         @Override
@@ -934,6 +929,11 @@ public void accept(LocationVisitor locationVisitor) {
             locationVisitor.visitPrimitiveField(getIndex(), 1);
         }
 
+        @Override
+        public int hashCode() {
+            return Objects.hash(super.hashCode(), allowInt);
+        }
+
         @Override
         public boolean equals(Object obj) {
             return super.equals(obj) && this.allowInt == ((DoubleFieldLocation) obj).allowInt;
@@ -1104,6 +1104,11 @@ public int primitiveArrayCount() {
             return DOUBLE_ARRAY_SLOT_SIZE;
         }
 
+        @Override
+        public int hashCode() {
+            return Objects.hash(super.hashCode(), allowInt);
+        }
+
         @Override
         public boolean equals(Object obj) {
             return super.equals(obj) && this.allowInt == ((DoubleArrayLocation) obj).allowInt;
@@ -1198,6 +1203,11 @@ public void accept(LocationVisitor locationVisitor) {
             locationVisitor.visitPrimitiveField(getIndex(), 1);
         }
 
+        @Override
+        public int hashCode() {
+            return Objects.hash(super.hashCode(), allowInt);
+        }
+
         @Override
         public boolean equals(Object obj) {
             return super.equals(obj) && this.allowInt == ((LongFieldLocation) obj).allowInt;
@@ -1283,6 +1293,11 @@ public void accept(LocationVisitor locationVisitor) {
             locationVisitor.visitPrimitiveArray(index, LONG_ARRAY_SLOT_SIZE);
         }
 
+        @Override
+        public int hashCode() {
+            return Objects.hash(super.hashCode(), allowInt);
+        }
+
         @Override
         public boolean equals(Object obj) {
             return super.equals(obj) && this.allowInt == ((LongArrayLocation) obj).allowInt;

truffle/src/com.oracle.truffle.api.object/src/com/oracle/truffle/api/object/Location.java

@@ -308,7 +308,7 @@ public boolean isConstant() {
     }
 
     /**
-     * Abstract to force overriding.
+     * Must be overridden in subclasses.
      *
      * @since 0.8 or earlier
      */
@@ -318,7 +318,7 @@ public int hashCode() {
     }
 
     /**
-     * Abstract to force overriding.
+     * Must be overridden in subclasses.
      *
      * @since 0.8 or earlier
      */
@@ -330,20 +330,15 @@ public boolean equals(Object obj) {
         if (obj == null) {
             return false;
         }
-        if (getClass() != obj.getClass()) {
-            return false;
-        }
-        return true;
+        return getClass() == obj.getClass();
     }
 
+    /**
+     * @since 0.8 or earlier
+     */
     @Override
     public String toString() {
-        String typeString = Objects.requireNonNullElse(getType(), Object.class).getSimpleName();
-        return typeString + getWhereString();
-    }
-
-    protected String getWhereString() {
-        return "";
+        return Objects.requireNonNullElse(getType(), Object.class).getSimpleName();
     }
 
     /**